Dacs, kits or bought?

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Tony Moore
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#16 Re: Dacs, kits or bought?

Post by Tony Moore »

Yes, my reclocker is the Kali.

I did previously use my own home-brew version made from D flip-flops and a Tent Labs clock but after many years it started giving me issues, probably a bad solder joint, which I couldn't track down so I switched to the Kali.

The Kali is very good. Plus it'll handle different base clock rates automatically and has a FIFO buffer. As always though, the power you supply it with matters. I am using a bog standard LM317 currently, but that was an improvement over smps. Maybe another super-regulator build in the future....where does this end? :roll:
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Nick
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#17 Re: Dacs, kits or bought?

Post by Nick »

All good points - I haven't looked at the jitter with a 'scope - the I2S from the Pi could well be jittery and therefore worthy of re-clocking...
This is the bit I have a problem with. From the days I did some messing with clocks and PLL's and CPLD's how can a i2s reclocker with the source clock (pi) and reclocker (its own xtal) deal with the fact there will be a difference in the clocking frequency. Will it not eventually have to miss a frame, or resend one?

It why USB to me seems a better connection between source and DAC than i2s because it is rate adaptive, so everything in the receiving side can be in the same clock domain and totally isolated (if needed) from the source.

BTW, AFAIK, there is no reason why i2c cant be used, I have thought (but never tried) of using a r2r multiplying DAC for audio, they are normally driven by i2c or SPI or TWI.
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Tony Moore
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#18 Re: Dacs, kits or bought?

Post by Tony Moore »

This is the bit I have a problem with. From the days I did some messing with clocks and PLL's and CPLD's how can a i2s reclocker with the source clock (pi) and reclocker (its own xtal) deal with the fact there will be a difference in the clocking frequency. Will it not eventually have to miss a frame, or resend one?
Yes, this is what also is a bit baffling. They _can_ only skip or resend frames, as you say, since they don't steer the clock frequency on the reclocker or source. It's not audible though, at least to my cloth ears. There is something inherently "urgh" about it though.
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Nick
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#19 Re: Dacs, kits or bought?

Post by Nick »

Well, I guess it will only happen now and then.
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soulman
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#20 Re: Dacs, kits or bought?

Post by soulman »

I'd go for a kit, in fact I did, the DDDac 1794. This was for several reasons, I'd heard a few of them in various guises and found them all to be very good, better, to my ears, than all of the oversampling dacs I'd heard. One other major reason is the fact that they can be easily upgraded, the new dac board has several upgrades (tent shunt regs and others) included and in it's most basic form (main board, dac board, output caps and decent psu) sounds like a dac costing a couple of thousand pounds. Better power supplies make a big difference, output transformers are another good step up and a Pi based streamer (with a kali reclocker) can be added for £100 or so.

All of this can be added or altered at a later stage, I'm currently adding a valve buffer (about £60 in total) which takes the sound further towards my ideal sound. If my enthusiasm seems excessive then accept my apologies, I am very enthusiastic because of the sound quality for cost and simplicity of the kit and room for improvement.
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Ray P
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#21 Re: Dacs, kits or bought?

Post by Ray P »

Nick wrote: Mon Aug 21, 2017 1:19 pm This is the bit I have a problem with. From the days I did some messing with clocks and PLL's and CPLD's how can a i2s reclocker with the source clock (pi) and reclocker (its own xtal) deal with the fact there will be a difference in the clocking frequency. Will it not eventually have to miss a frame, or resend one?
My reclockers (Acko SO3 and Twisted Pear Cronus) both use the reclocker clocks to drive the Beaglebone Black (via isolators and having disabled the BBB clock). My Buffalo IIIse implementation runs in full sync with the reclocker oscillators clocking the BBB, the reclocker and the DAC. There are two oscillators for 44.1 and 48KHz data families.
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Ant
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#22 Re: Dacs, kits or bought?

Post by Ant »

The only one on fleabay I can find that fits the bill connectivity wise is this one

http://www.ebay.co.uk/itm/272158371935.

I haven't a clue wether the chipset is any good, and it looks like there is an internal jumper to select the coax or optical input. Not exactly what I wanted though as it is already assembled.

Presumably I can fudge a switch onto the jumper pins to select the input on the fly with a bbm switch, and it does come with a reg board.

Obviously a case for it is no problem.

Worth a look? Im so far out of the loop with digital that it could be a right crock of shit and I wouldnt know :D
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#23 Re: Dacs, kits or bought?

Post by Neal »

Ant, you are welcome to my biscuit tin DAC. Earlier version than your eBay link but has 8146/4397. Its not going to blow your socks off!

I can bring it up when I collect the G99.... if you can wait that is....

http://i94.photobucket.com/albums/l82/_ ... CF6797.jpg
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#24 Re: Dacs, kits or bought?

Post by Ant »

That'd be great, a point of comparison with the beresford thanks neal
Cant see the link BTW, the photobucket speedo of doom appears instead
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pre65
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#25 Re: Dacs, kits or bought?

Post by pre65 »

Ant wrote: Mon Aug 21, 2017 10:04 pm That'd be great, a point of comparison with the beresford thanks neal
Cant see the link BTW, the photobucket speedo of doom appears instead
That's strange, 'cos I get to see the picture. :?
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Ray P
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#26 Re: Dacs, kits or bought?

Post by Ray P »

Ant wrote: Mon Aug 21, 2017 8:19 pm The only one on fleabay I can find that fits the bill connectivity wise is this one

http://www.ebay.co.uk/itm/272158371935.

I haven't a clue wether the chipset is any good, and it looks like there is an internal jumper to select the coax or optical input. Not exactly what I wanted though as it is already assembled.

Presumably I can fudge a switch onto the jumper pins to select the input on the fly with a bbm switch, and it does come with a reg board.

Obviously a case for it is no problem.

Worth a look? Im so far out of the loop with digital that it could be a right crock of shit and I wouldnt know :D
Ant, I wouldn't be tempted. maybe take a look at the DIYINHK offerings instead. A little more expensive but, I think, better quality and more proven. Tweakable too.

http://www.diyinhk.com/shop/audio-kits/ ... nd_led_pcb

http://www.diyinhk.com/shop/audio-kits/ ... input.html

Or another alternative would be the JLSounds USB DAC modules, their I2SoverUSB, AK4490 and LME49710 kit combo for example.

http://www.jlsounds.com/combos.html

You would need some power supplies but I can let you have some good quality TPSA4700 modules.

Ray
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Neal
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#27 Re: Dacs, kits or bought?

Post by Neal »

Blasted photobucket!

I'll have to move my pics......

Image
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ed
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#28 Re: Dacs, kits or bought?

Post by ed »

Neal....

the moment I saw that my knuckles were in my mouth....for my piece of mind is there any chance you could put an old credit card underneath the chocolate block......

just sayin cos the number of times I've had 1 wire come out of a block for no reason is...well...more than once..no idea why it happens but it does......
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SteveH
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#29 Re: Dacs, kits or bought?

Post by SteveH »

The protective earth connection to the metalwork should have its own seperate nut and bolt/stud.
Neal
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#30 Re: Dacs, kits or bought?

Post by Neal »

It's fine, the Tx frame is the strongest part to bolt the earth lead to plus there is a star washer under there....besides Ant will no doubt re-case it.
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